mplab c18 c compiler getting started - Computer & Information Science

MPLAB ® C18 C Compiler Getting Started
4.2.6 Summary for Program 1 “Hello, world!”
This completes the first program example. These topics were covered:
Writing MPLAB C18 code
Building (compiling and linking) the project
Testing the project with MPLAB SIM
Troubleshooting beginner errors
4.3 PROGRAM 2: LIGHT LED USING SIMULATOR
The first example demonstrated the basics of creating, building and testing a project
using MPLAB C18 with the MPLAB IDE. It did not go into the details of what the target
processor would do with that code. In this next program, code will be generated to
simulate turning on a Light Emitting Diode (LED) connected to a pin of the PIC18F452.
4.3.1 Create a New Project
Create a new project named “GS2” in a new folder named “Second Project.”
Make sure the language tools are set up and the Build Options properly configured as
shown in Section 3.7 “Verify Installation and Build Options”.
4.3.2 Write the Source Code
Create a new file and type in the code shown in Example 4-3. Save it with the name
main.c in the “Second Project” folder:
EXAMPLE 4-3: PROGRAM 2 CODE: main.c
#include
#pragma config WDT = OFF
void main (void)
{
TRISB = 0;
}
/* Reset the LEDs */
PORTB = 0;
/* Light the LEDs */
PORTB = 0x5A;
while (1)
;
The first line in this code includes the generic processor header file for all PIC18XXXX
devices, named p18cxxx.h. This file chooses the appropriate header file as selected
in MPLAB IDE; in this case, the file named p18f542.h (which could have been
included explicitly instead). This file contains the definitions for the Special Function
Registers in these devices.
“#pragma config WDT = OFF” is the same as in the first program.
Note: In MPLAB C18, the main function is declared as returning void, since
embedded applications do not return to another operating system or
function.
DS51295F-page 44 © 2005 Microchip Technology Inc.